Method of erecting buildings



Oct. 11, 1955 P. N. YOUTZ 2,720,017

METHOD OF' ERECTING BUILDINGS Filed April 22, 1953 s Sheets-Sheet 1 i; @(MGMMMMMMM'E MIME/V701? PHIL [P M YOUTZ 14 7' TOR/VARY Oct. 11, 1955 P. N. YOUTZ 2,720,017

METHOD OF ERECTING BUILDINGS Filed April 22, 1953 5 Sheets-Sheet 2 a 7 P/a/a 26 Oct. 11, 1955 Filed April 22, 1953 P. N. YOUTZ METHOD OF ERECTING BUILDINGS 3 Sheets-Sheet 3 I/Vl/E/I/TOR PHIL/P M V0072 arm CM 19 7' THE/V5 Y United States PatentO METHOD OF ERECTING BUILDINGS Philip N. Youtz, Yorktown, N. Y., assiguor to, Institute of lltiylentive Research, San Antonio, Tex., a trust estate exas Original application November 30, 1948, Serial No. 62,771, now Patent No. 2,686,420, dated August 17, 1954. Divided and this application April 22, 1953, Serial No. 350,313

4 Claims. (Cl. 25-155) This invention relates to building construction and especially to the erection of the columns and floors of a building.

The method now most commonly employed in erecting buildings with concrete floors is to pour the floors in situ as the erection of the building proceeds. This involves the building of forms for the various floors and centering to support the forms, and also the operation of elevating the cement for any floor to the level which the floor is to occupy in the building preparatory to pouring it into the completed form, all of which involves considerable labor and expense. One object of the present invention is to provide a novel and practical method of erecting a building with concrete floors by which the expense and time involved in pouring the floors in situ is very appreciably reduced, thereby correspondingly reducing the over-all cost of erecting the building.

It has heretofore been proposed to erect a building having concrete floor slabs which involves pouring the ground floor slab and then pouring the upper floor slabs at ground level on the ground floor slab, thereby to form a stack of floor slabs which are resting on the ground floor slab, and subsequently raising the upper floor slabs to their appoined positions in the building.

A further object of the present invention is to provide a novel method of thus raising the various upper floor slabs from the stack of floor slabs which havebeen poured at ground level to their appointed positions in the building and permanently supporting them in such positions. By pouring the upper floor slabs one on the other each floor slab, after it has been poured and has hardened to a sufficient extent, constitutes both the main portion of the form for the floor next above and the entire centering therefor.

In pouring any floor the only thing in the way of a fabricated form which is necessary is a peripheral wall or screed to determine the outline of the floor.

The labor and expense of elevating the concrete mix for any floor to the level which it is to occupy in the building is also eliminated as all floors are poured at ground level.

In erecting a building having steel columns and concrete monolithic floors in accordance with my system, the procedure is substantially as follows.

The ground is first leveled and smoothed for the ground floor, which may be a cellar floor or a basement floor or a floor at ground level. Excavations are then made below the ground floor level for the footings of the structural columns for the building and trenches are dug for the peripheral foundations. The footings for the columns and the peripheral foundations may, if desired, be cast directly in the ground and without the use of specially built forms.

The structural columns for the building are then set up on the footings and secured thereto, after which the reinforced ground floor is poured around and in contact with the columns, whereby when the floor has set it serves to brace the columns in all directions.

2,720,017 Patented Oct. 11, 1955 Each structural column is provided with integrally interconnected broad vertically-disposed load-bearing surfaces as will be presently described.

The finished ground floor, which as stated above may be the cellar floor or a basement floor, or a floor at ground level, is then entirely covered with tar paper or similar waterproof separating material preferably in thin film-like form, and a collar is placed on the separating material around each column.

The second floor is then poured as a unit directly on the covered ground floor, said second floor unit being in the form of a monolithic slab. Before the second floor is poured, however, a suitable screed or wall will be built to determine the edge contour of the second floor. The collars above referred to serve to keep the concrete material of the second floor from contacting the columns and provide said floor with openings through which the columns pass. They also function as lifting plates to which the lifting apparatus can be attached for raising the floor, and in addition they constitute supporting plates for the floor after it is connected to the column as will be hereinafter described.

During the pouring of the second floor the ground floor functions not only as the form for the second floor, with the exception of the peripheral wall, and also as the centering forsupporting the weight of the second floor.

The use of the tar paper or other film-like separating material as a cover for the ground floor and onto which the second floor monolithic slab is poured is an important feature because it prevents any bond developing between the ground floor and the second floor as the latter is setting.

If the building is to be a one-story building, the second floor monolithic slab will constitute the roof of the building, and after it has set properly, then it is raised as a single unit into its position in the building by lifting means associated with the columns. After the monolithic second floor slab has been elevated into its permanent position, it is then permanently connected to the columns, During this lifting operation, the entire weight of the seocnd floor is carried by the columns.

The fact that each column is anchored at its lower end to its footing, which is located a distance below the ground floor, and is also braced laterally in all directions by the ground floor is important as by this means the columns are firmly held in their correct vertical positions and are prevented from deflection While they are support-. ing each floor slab as it is being raised.

While any suitable lifting means may be used, I preferably employ hydraulic jacks which are-mounted on top of the columns which are connected to the floor slab to be lifted by elongated lifting members.

If the building is to be one having two or more stories, then after the second floor monolithic slab has been poured and has set and while it is still at ground level, the third floor slab is poured directly on the second floor slab, as above described, and this procedure will be repeated until all the necessary floor slabs and the roof slab have been poured, each floor slab being in the form of a monolithic slab and all the floor slabs resting on the ground floor in superposed relation.

It will be understood that a separating film-like layer will be laid on each floor slab before the next floor is poured thereon so as to prevent the suporposed slabs from becoming bonded together.

After all the floor slabs have been thus poured at ground level, the top floor slab is raised by lifting means associated with the columns as above described to a position somewhat above the predetermined position for the second floor of the building being erected and is temporarily secured to the columns. The same operation is repeated with respect to all the other floor slabs except the second floor slab, as a result of which all of the floor slabs except the second floor slab will be temporarily secured to the columns at positions slightly above the permanent position for the second floor.

The second floor slab is then similarly raised to its permanent position and permanently secured to the columns. After this has been done, the top floor slab and the other floor slabs above the third floor slab are raised one by one to .positions'slightly above the third floor level and each floor slab is temporarily secured to the columns. ,The third floor slab is then similarly raised to its permanent position in the building and permanently secured to the columns.

The above operation is-repeated until all floor slabs have been lifted to their proper levels and permanently secured tothe columns. In raising the various floor slabs after the top floor slab has been raised and temporarily secured to the columns, the elongated lifting members are first lowered through the lifted floor slab and attached to the next floor slab to be lifted, and the lifting force is again applied to the lifting members by the jacks located at the tops of the columns, said lifting members moving upwardly through the lifted floor slab as the floor slab attached to said members is being lifted.

In order to give an understanding of my invention, I

have illustrated in the drawings a selected embodiment thereof which will now be described, after which the novel features will be pointed out in the appended claims. Inthe drawings:

' Fig. l is a perspective view illustrating my improved system and showing a building construction in which the columns have been erected, the ground floor poured and the second floor also poured on the ground floor.

Fig. 2 is an enlarged plan of the portion of a floor through which a column extends, the column and the tension screw being shown in section.

Fig. 3 is a sectional perspective view showing part of excavations are so made that the footings 3 will be located some distance below the level for'the ground the lifting yokes by which the monolithic floor slabs are lifted into position.

Figs. 4, 5 and 6 are diagrammatic views showing various steps in the erection, in accordance with my invention, of a building which has five floors and a roof slab.

Fig. 7. is a fragmentary elevation illustrating one of the columns with its lifting jack and also illustrating the ground floor with the second floor poured directly thereon. Fig. 8 is a view of the tension or lifting screw.

f Fig. 9 is a fragmentary view showing the foot at the lower end of the tension screw.

. Fig. 10.illustrates the jack support which is mounted on each column.

Fig. 11 is a plan showing lifting yoke in position.

Fig. '12 is a fragmentary sectional view showing the operation of the safety wedges.

Fig. 13 is a view illustrating the building operation in accordance with my invention showing the second floor after it has been raised and connected to the column.

Fig. 14 is a plan view of the collar which is used when pouring all floors above the ground floor.

Fig. 15 is a plan showing blocking used for bracing collar rigidly to the column.

Figs. 16 and 17 are standard angle iron connections by which the various floors can be attached to the columns after they have been raised.

. As stated above, the first step in erecting a building in accordance with my invention is to level the ground 1 where the building is to be located preparatory to pouring the ground floor, which as stated above, may be a cellar floor, or a basement floor, or a floor at ground level.

The next operation is to provideexcavations 2 for the footings on which the supporting colums are to be erected and then to pour the footings 3 in said excavations. The

floor. After the footings are properly set, then the columns 4 are erected thereon and are anchored thereto in any suitable or usual way, said columns eventually constituting the supporting columns for the building when it has been erected. As shown in Fig. 7, the footing 3 has anchor bolts 5 embedded therein which extend through a bearing plate 6 welded or otherwise secured to the bottom of the column 4 and which carry clamping nuts 7 by which the foot plate 6 is anchored to the foot- Any number of columns 4 maybe used depending upon the size and character of the building. As illustrating the invention, there is shown in Fig. 1 of the drawings a building which would require four columns 4, and these are shown as located well inside the marginal edges of the building. The location of the columns, however, may be varied and will depend upon the design and character of the building being erected The columns herein shown are steel columns having a wide flange or H section, but the invention is not limited to, any particular type of column, and columns of concrete or other material may be employed withoutdeparting from the invention.

The columns 4 as initially erected will preferably have a length to extend somewhat above the position in the building to be occupied by the second floor.

After the columns have thus been erected, then the ground floor 8 is poured, and in many instances it will be satisfactory to pour it directly on the ground surface prepared for it. In pouring the ground floor the cement is poured around and in contact with the columns 4 so that when the ground floor has set, it will serve to brace the columns from all directions.

After the ground floor 8 has set properly, then the second floor slab 9 is poured directly on the ground floor slab. Before this is done, however, the ground floor 8 is entirely covered with tar paper 41 or some other suitable waterproof material in film-like form, so as to prevent the second fioor slab, when poured, from adhering or bonding to the ground floor. If desired, fine sand may be sprinkled on the ground floor before the tar paper is applied. Furthermore, before the second floor slab 9 is poured, a collar 10 is placed around each column directly on the layer 41. This collar has an opening 11 through which the column extends and it is provided with a vertical wall 12 having a vertical dimension approximately equal to the thickness of the second floor slab and is also provided with a base flange 13 extending outwardly in all directions, which flange 13 is provided with bolt holes 14. When each collar is placed in position on the layer 41 around a column,- bolts 15 are inserted upwardly through the holes 14 of the base flange 13 with the heads of the bolts on the under side of the flange 13, and these bolts are preferably covered with paper so as to prevent the concrete of the second floor from bonding thereto. The bolts have a length somewhat greater than the thickness of the second floor slab.

After each column has been provided with its collar 10 as above described and the ground floor slab has been covered with the separating sheet 41, then the second floor slab 9 is poured on the ground floor and at ground level. It will be understood that before this is done, a screed or curb will have to be built around the periphery of the floor so that the second floor slab when poured will have a proper peripheral shape. This building of such a screed or curb is a simple and inexpensive matter however.

The second floor slab 9, when poured, is in the form of a monolithic slab and may constitute the complete second floor unit. It will be understood that this monolithic second floor slab will be provided with the usual steel reinforcings. During thev pouring of the second floor slab 9 the ground floor 8, together with the. peripheral screed or curb, functions as the form or mold for said second floor slab, and the groundfloor slab also provides the support or centering for supporting the second floor slab as it is poured. Said second floor slab is thus poured without the use of the expensive form and centering now commonly employed when pouring concrete floors.

If the building being erected is a one-story building, then the monolithic second floor slab 9 which has been poured at ground level will constitute the roof slab of the building, and after the said second floor slab has set properly, it is then raised as a unit into its permanent position in the building and secured permanently to the columns. For thus raising the monolithic second floor slab 9, I propose to use elongated lifting members 16 in the form of tension screws or' screw-threaded lifting rods, one for each column, and to attach the lower ends of the lifting rods to the second floor slab 9 and to provide means at the upper ends of the columns for acting on said lifting rods and raising them thereby lifting the second floor slab into its permanent position. These lifting rods 16 may conveniently be located between the flanges of the columns 4 as shown in Figs. 1 and 2. For connecting the lifting rods to the floor slab to be lifted, I have employed lifting elements 17 which are secured to the second floor slab through the medium of the bolts 15 above referred to as best seen in Fig. 7. Each lifting element 17 has associated with it a latch 18 which has a bifurcated inner end 19 adapted to embrace the lower end of the corresponding lifting rod 16. Each lifting rod 16 .is formed at itslower end with a foot 20 which engages the under side of the latch 18, so that when a lifting force is applied to the lifting'rod 16, it will operate through the latch 18 and the lifting element 17 to raise the second floor slab 9.

The latch 18 is shown as movably mounted in the lifting element 17 so that it can be withdrawn from engagement with the lifting rod and for this purpose said latch has a handle 21 on its outer end which may be grasped for withdrawnig it from engagement with the lifting rod.

As stated above, each lifting rod 16 cooperates with means located at the top of and mounted on the corre sponding column for applying the necessary lifting force to the lifting rod to raise the floor slab so that the entire weight of the second floor slab 9 as it is raised is carried by the columns 4.

One form of lifting means is a center hole hydraulic jack 22 one of which is mounted on each column 4 in a position so that the corresponding lifting rod 16 extends through the center'of the jack. Such center hole hydraulic jacks are in common use and therefore a detailed de scription of them is not deemed necessary. Each lifting jack 22 is carried on a jack support which comprises a jack supporting plate 23 mounted on the column and secured thereto by angle members 24 and on which the jack 22 is supported and also comprises a top supporting plate 25 which is supported on the jack supporting plate 23 by means of supporting elements 26.

The lifting rod 16 for each jack extends looselythrough both plates 23 and 25 and through the jack 22, and it has screw threaded thereto two nuts 27 and 28, the nut 28 being located above the top plate 25 and the nut 27 being located between the jack 22 and thetopplate 25. 1

In raising the second floor slab 9, the jacks will be in their lowered position and the nuts 27 (which may be referred to as lifting nuts) are screwed down into contact with the rams of the jacks. The jacks are then operated and by their engagement with the lifting nuts 27, they raise the lifting rods 16 and the second floor slab 9 one upward step, the lifting rods moving upwardly through both plates 23 and 25. The nuts 28 (which may be de. scribed as holding nuts) are then turned down on the lifting rods 16 into engagement with the corresponding top supporting plate 25 and the ram of each jack is then lowered ready for its next operation and each lifting nut 27 is turned down on its lifting rod 16 into engagement with the lowered ram of the holding jack. The. engagement of the nuts 28 with the top supporting plates 25 serve to prevent retrograde movement of the lifting rods and the load supported thereby while the jacks are being lowered.

The above operations are repeated over and over again thereby raising the second floor slab 9 step by step to the position it is to occupy in the building, which position is indicated by the dotted lines in Fig. 7 and in full lines in Fig. 13.

As a precautionary safety measure, I propose to use safety devices which cooperate with each of the collars 10 in the floor 9, which safety devices permit the rising movement of the floor slab but become operative automatically to prevent any downward movement thereof, thereby preventing the floor slab from falling should any of the lifting equipment fail.

While any suitable form of safety device may be employed, that herein shown comprises pairs of wedges 35, 36 interposed between the flat flange of each column and the vertical wall 12 of the collar 10. The wedge 35 of each pair is widest at the top and thinnest at the bottom and is secured to the collar in some suitable way. The Wedge 36 has its thin edge at the top and its wide end at the bottom and it is supported by suitable springs 37 which normally hold it in the position shown in Fig. 12.

As the floor slab 9 is raised, the yielding support for the Wedges 36 allow them to yield downward slightly so as to permit the floor slab to be freely moved upwardly. If, however, the floor slab should tend to move downwardly, the springs 37 together with the friction of the wedges 36 against the column will crowd the wedge members 36 between the coltunn and the wedge members 35 and will therefore lock the floor slab against downward movement. The wedges 35, 36 fill the space between the fiat sides of each column and the walls of each Collar 10 and thus prevent side sway of the floor as it is being raised. In other words, the collars are so made that the openings therethrough closely fit the flat faces of the columns.

When the second floor slab 9 has been thus raised to its permanent position, it is then permanently secured to the columns 4 in any suitable or usual way, as by means of supporting brackets 40, the wedges 35 and 36 are removed and blocking 38, 39 is inserted between each column and the vertical walls 12 of the corresponding collar 10 thus locking the columns and their collars from any relative movement. The jacks 22, the jack supports, the tension screws 16 and the lifting elements 17 may then be removed, and the building is in condition to have the walls built in any known or usual way. The portions of the faces of the columns 4 which closely fit the openings in the collars 10 and with which the collars are in engaged sliding and guiding relation during the ascent of the slab may be referred to, generally, as integrally interconnected, broad, vertically disposed load-bearing; surfaces. The spaced relation between the columns 4 provides a pluralllity of such bearings surfaces in spaced relation to each 0t er.

If the building is to have more than one story, then after the second floor slab has been poured and has set, the third floor slab will be poured directly on the second floor slab at ground level as above described and, if the building is to have a fourth floor slab, a fourth floor slab will be poured on the third floor slab also at ground level, this operation being repeated until all the floor slabs have been poured, one on the other, at ground level as illustrated in the diagram shown in Fig. 4, wherein 8 indicates the ground floor slab, 9 the second floor slab, 29 the third floor slab, 30 the fourth floor slab, and 31 the fifth floor slab, the columns in said figure being indicated at 4. It will be understood that before each floor slab above the second floor slab is poured, the floor slab on to which it is to be poured will be covered with a filmlike layer 7 of tar paper or some other suitable separating material which will prevent the floor slab to be poured from bonding to the floor'slab on to which it is poured as stated with respect to the pouring of the second floor slab 9 on the ground floor slab 8. 1 t

Prior to pouring each floor slab, a collar 10 is placed around each column on the floor slab below and the bolts for the lifting elements are inserted through the holes 14 in the flanges 13 as above described. In order to avoid any interference between the bolts 15 in any floor slab with the bolts in the floor slabs above and below, it is proposed to make the holes 14 in pairs, and as shown in Fig; 14, there is a pair of holes 14 at each corner of the flange 13.

-When 'anyfloor slab of a multi-story building is to be poured, for instancefioor slab 9 in Fig. 4, the bolts 15 will be placed in one hole 14 of each pair of holes, each bolt being wrapped in paper so as to prevent it from becoming bonded to the concrete when the floor slab is poured.,

When the next floor slab, for instance the floor slab 29 in Fig. .4, is to be poured, a collar 10 with a bolt 15 extending through one hole 14 of each pair of holes :is placed around each column'on the floor slab last poured, and in locating the bolts, they are placed in the other hole of. each pair of holes from that in which the bolts in the collars .of the floor slab below are located. When the collars .10 for the floor slab 29 are placed in position, the upper exposed ends of the bolts 15 in the floor slab below will extend through the empty holes 14 in said collars for the floor slab 29, and there will therefore be no interference between the bolts in each floor slab and those in the floor slabs below and above. These operations are repeated until the required number of floor slabs have been poured.

- After all the floor slabs have thus been poured at ground level one on another in superposed relation, then each of the floor slabs above the second floor slab 9 will be raised separately as above described to a position slightly above the second floor level and each, as it is raised, will be temporarily secured to the columns 4. The second floor slab 9 is then raised as above described andpermanently secured to the columns.

, It should be'stated that after the top floor slab has been raised and temporarily secured to the columns 4, then lifting elements 17, one for each column, will be secured to the next floor slab below, that is, the then top floorslab on the stack of superposed floor slabs, the lifting rods 16 will be disconnected from the raised floor slab and the lifting nut 27 and holding nut 28 on each lifting rod 16 will be turned to lower said rod into position to beconnected to the corresponding lifting element on the top floor slab of the stack of superposed floor slabs.

During this operation of lowering the lifting rods for connection to the next floor slab to be lifted, such rods pass down through the raised floor slab. It will be noted that each lifting rod 16 is located between the flanges of the corresponding column 4 and thus is in a position to be lowered through the corresponding collar 10 of the floor slab which has been lifted and temporarily attached to the columns.

The jacks 22 are then actuated so as to lift the latter floor slab (which is the next fioor slab to be lifted) into a position slightly below the previously raised floor slab but above the second floor level, and said floor slab will then be temporarily secured to the columns. During this slab lifting operation the lifting rods 16 move upwardly through the collars 10 of the floor slab which has already beenlift ed and temporarily secured to the columns.

This operation will be repeated for each of the floor slabs in thestack of floor slabs until the second floor slab of the building is raised to its proper position and permanentlysecured to the column.

Atthisstage in the building operations the second floor slab of1thebuilding will be located in its permanent position in the building'and will, have been permanently secured to the columns, all the floor slabs abovebeing located slightly above the second floor slab and being temporarily secured to the columns.

The operation of lifting each. floor slab involves. lowering the lifting rods 16 down through the collars 10. of the floor slabs which have been previously lifted and connecting said rods to the slab to be lifted. .If the columns as initially erected extend only slightly above. the second floor level, thenan additional column section will be mounted on each column so as to carry it slightly above the third floor level. Before this is done, however, the jack supports will have to be removed from the top of the columns'as initially erected, and after the additional column section has been mounted, then said jack supports are in turn mounted on and attached to the top of the extended column and the lifting rods areplaced in position ready for cooperation with the jacks in again raising one bylone the various floor slabs that have been temporarily attached to the columns. The abovev described operations of raising the floor slabs one by one .will'then be repeated to raise all floor slabsabove the third floor slab into positions slightly above the third floor slab level, each floor being temporarily secured to the columns when so raised, and the third floor slab will be raised into its permanent position and permanently secured to the columns.

These operations are repeated until each of the floor slabs has been brought .into its permanent location in the building and permanently secured to the columns.

While my invention is especially applicable for use in erecting buildings having concrete floors, yet the same system might also be usedin erecting buildings that have other types of fioorssince the invention involves building each of the floors as a unit at ground level and in superposed relation, and then raising the floors to their proper positions in the building, floor by floor and story by story, each floor being permanently secured to the supporting columns when it has been finally lifted into its proper .position.

While in carrying out my invention I preferto employ supporting columns which are .to be the permanent structural columns of the building, yet certain features of the invention would not be departed from if the columns first erected were temporary columns which were used in raising the floors to their proper level and which were subsequently replaced by permanent structural columns or piers or hearing walls.

Inorder to relieve the floor or roof slab from undue strain during the raising movement thereof, it is important to, maintain the slab at all times in a true horizontal position so that the rising movement at every pointin the slab is exactly the same. When this condition obtains, the separating movement between the slab being lifted and the slabv immediately beneath will take place practically simultaneously at all points in the under face of the rising slab, this being possible by virtue of the presence of the separating sheet between the slabs.

This application is a division of my co-pending application, Serial No. 62,771 filed November 30, 1948, now Patent No. 2,686,420.

I claim; 1

1. A method of erecting a building which comprises the steps of erecting a plurality of vertical supporting members for the building secured at their lowermost ends to a. foundation support, each of said supporting members comprising a single structural unit having spaced integrally interconnected broad vertically-disposed load-bearing surfaces, forming a first slab for the building which surrounds each of said supporting members, covering the top surface of said first slab with a separating layer of bond-preventing material, casting a monolithic concrete slab directly upon said separating layer with openings therein around each of said supporting members and forming said openings-with vertical faces disposed in slidable engaged relation with said broad, load-bearing surfaces of said supporting members, and forming addi tional openings in said monolithic slab laterally spaced from each of said openings surrounding a supporting member, securing separate lifting meansto said supporting members, interconnecting said monolithic slab at one of said openings spaced laterally from said opening around the supporting member through said lifting means to said vertical supporting member, operating said lifting means to elevate said monolithic slab perpendicularly to a predetermined point on said vertical supporting members, maintaining the vertical faces in each of said openings around the vertical supporting member extending therethrough in engaged sliding and guiding relation with said adjacent broad, load-bearing surfaces of said vertical' supporting member throughout the ascent of said monolithic slab, and thus maintaining said vertical faces of said openings around said vertical supporting members in load-transmitting relation with said load-bearing sur faces of said members to prevent sidesway of said monolithic slab during its ascent, and securing said elevated monolithic slab to said vertical supporting members.

2. A method of erecting a building which comprises the steps of erecting a plurality of vertical supporting members for the building secured at their lowermost ends to a foundation support, each of said supporting members comprising a single structural unit having spaced integrally interconnected broad vertically disposed loadbearing surfaces, forming a first slab for the building which surrounds each of said vertical supporting members, covering the top surface of said first slab with a separating layer of bond-preventing material, casting a monolithic concrete fioor slab directly upon said separating layer with openings therein around each of said vertical supporting members, covering the top surface of said floor slab with a layer of said separating material, casting a monolithic concrete roof slab directly upon said separating layer with openings therein around each of said vertical supporting members, forming each of said openings in said floor and roof slabs with vertical faces disposed in slidable engaged relation with said broad, load-bearing surfaces of said vertical supporting members and forming additional openings in said floor and roof slabs laterally spaced from each of said openings therein surrounding a vertical supporting member, securing separate lifting means to said supporting members, interconnecting said monolithic roof slab at one of said openings spaced laterally from the opening around the supporting member through said lifting means to said vertical supporting member, operating said lifting means to elevate said monolithic roof slab perpendicularly to a predetermined point on said vertical supporting members, maintaining the vertical faces in each of said openings around the vertical supporting member therethrough in engaged sliding and guiding relation with said adjacent broad, load-bearing surfaces of said vertical supporting member throughout the ascent of said monolithic slab, and thus maintaining said vertical faces of said openings around said vertical supporting members in load-transmitting relation with said load-bearing surfaces of said members to prevent sidesway of said monolithic slab during its ascent, securing said elevated monolithic roof slab to said vertical supporting members, interconnecting the said monolithic floor slab at one of the said openings spaced laterally from the openings around the supporting members through said lifting means to said vertical supporting member, operating said lifting means to elevate said floor slab perpendicularly to a predetermined point on said vertical supporting members, maintaining the vertical faces in each of said openings around the vertical supporting member extending through said monolithic floor slab in engaged sliding and guiding relation with said adjacent broad, load-bearing surfaces of said vertical supporting member throughout the ascent of said monolithic floor slab, and thus maintaining the vertical faces of said 1T0 openings around said vertical supporting members in load-transmitting relation with said load-bearing surfaces of said members to prevent sidesway of said monolithic floor slab during its ascent, and securing said elevated monolithic floor slab to said vertical supporting members.

3. A method of erecting a building which comprises the steps of erecting a plurality of vertical supporting members for the building secured at their lowermost ends to a foundation support, each of said supporting members comprising a single structural unit having spaced integrally interconnected broad vertically disposed loadbearing surfaces, forming a first slab for the building which surrounds each of said vertical supporting members, covering the top surface of said first slab with a separating layer of bond-preventing material, casting a plurality of monolithic concrete slabs upon said separating layer covering said first slab in superposed relation with separating layers therebetween and with openings therein around each of said vertical supporting members, and forming said openings in each of said monolithic concrete slabs with vertical faces disposed in slidable engaged relation with said broad, load-bearing surfaces of said vertical supporting members, and forming additional openings in said monolithic concrete slabs laterally spaced from each of said openings surrounding a vertical supporting member, the uppermost of said monolithic con crete slabs being a roof slab and the lower monolithic concrete slabs being floor slabs, securing separate lifting means to said supporting members, interconnecting said monolithic roof slab at one of said openings spaced laterally from the opening around the supporting member through said lifting means to said vertical supporting member, operating said lifting means to elevate said monolithic roof slab perpendicularly to a predetermined point on said vertical supporting members, maintaining the vertical faces in each of said openings around the vertical supporting member therethrough in engaged sliding and guiding relation with said adjacent broad, load-bearing surfaces of said vertical supporting member throughout the ascent of said monolithic roof slab, and thus maintaining said vertical faces of said openings around said vertical supporting members in load-transmitting relation with said load-bearing surfaces of said members to prevent sidesway of said monolithic slab during its ascent, securing said elevated monolithic roof slab to said vertical supporting members; interconnecting each of said lifting means through one of said laterally spaced openings with the next lower monolithic concrete floor slab at one of said openings spaced laterally from said. opening around said supporting member to which said lifting means is secured, operating said lifting means to elevate said next lower monolithic floor slab perpendicularly to a predetermined point on said vertical supporting members, maintaining the vertical faces in each of said openings therein around the vertical supporting member extending therethrough in engaged sliding and guiding relation with said adjacent broad, load-bearing surfaces of said vertical supporting member throughout the ascent of said monolithic floor slab, thus maintaining said vertical faces of said openings around said vertical supporting members in loadtransmitting relation with said load-bearing surfaces of said members to prevent sidesway of said monolithic floor slab during its ascent, securing said elevated floor slab to said vertical supporting members, and repeating said steps for elevating and securing said monolithic concrete floor slab, sequentially, to elevate each next lower monolithic concrete floor slab until all of said monolithic concrete floor slabs have been elevated and secured to said vertical supporting members at predetermined points thereon.

4. The method of claim 3 which includes the steps of first elevating said monolithic concrete roof slab to a temporary position on said vertical supporting members, temporarily securing said roof slab to said vertical supporting members, separately elevating, in sequence, all

'-' 11 but the lowermost of said monolithic concrete floorslabs to, temporary positions'on said vertical supporting mem bers and temporarily securing said monolithic floor slabs to said vertical supporting members, elevating said lowermost monolithic floor. slab to a permanent. position on said vertical supporting members, permanently securing said lowermost floor slab to said vertical supporting meme bers, and, thereafter, elevating said monolithic concrete roof slab and said upper monolithic concrete floor slabs to permanent positions on said vertical supporting members and permanently'securing said roof and upper floor slabs to said vertical supporting members.

References Cited in the file of this patent UNITED STATES PATENTS Peltzer July 1, 1913 Halverson et al. Dec. 30, 1919 Crozier Jan. 31, 1928 Lafiaille Feb. 6, 1951 FOREIGN PATENTS Great Britain Sept. 6, 1948 

